What distinguishes art from commerce and why do artists continue to create in a seemingly indifferent world?

Three actors rehearse a play about three theater artists at different points in their careers: Cindy, a budding playwright who is studying (and having an affair) with her professor Dale, who chose a career in academia over moving to New York and trying for an acting career, and Dale's old flame Eleanor, who did actually move to New York all those years ago and, after plugging away for nearly two decades, has just won the Pulitzer for Drama -- and is invited to speak at Dale's college. While rehearsing this play, the three actors are forced to reassess their own careers, motives, goals, definitions of success/failure. At stake is their respect for each other (and themselves) as they question their identity as artists.